Free radicals such as ROO can react at random by hydrogen abstraction and a variety of reactions to damage proteins, lipids and vitamins. Many diseases, such as atherosclerosis, inflammation and Perkinson's disease have been proven to be caused by oxygen-derived free radicals.In this study, we succeeded the efficient synthesis of O^4, O^9-dimethylstealthin A and C,methylated derivatives of potent radical scavengers produced by Streptomyces viridochromogenes, using Suzuki coupling reaction as a key step. This work offers new, rather stable and useful compounds for studying free radical scavenging actions.